The invention relates to a backup system and method for acquiring backups in a plurality of storage systems.
Recently, there has been a trend in computer systems toward distribution systems, mainly client server systems, and away from computer systems that collectively manage basic business such as banking and securities-related business using large-sized computers. In such a distribution system environment, a configuration where requests from clients are processed by multiple servers and multiple disk array systems in a cluster structure is adopted. JP-A-2003-99306 discloses highly available clusters as described above, with data centers not only at a primary site, but also at secondary site located a long distance away from the primary site, in which data is duplicated by means of remote copying, so that a local disaster such as an earthquake will not result in complete loss of all data.
A snapshot function is also known as one of the backup functions in client server systems, as disclosed in JP-A-2003-532191. Vendors supply various products equipped with the snapshot function. For example, VSS (Volume shadow copy service) supplied by Microsoft® is a service for providing a common infrastructure for snapshot creation to backup-related hardware and software such as back-up software, server application programs, and storage hardware. In backup processing by VSS, a snapshot is created and then back-up data is acquired from the snapshot. Accordingly, the backup data can be created without stopping the running server application program.